JP2567413B2 - Broadcast-related data multiplex broadcast receiver using preset channel memory - Google Patents

Description

TECHNICAL FIELD The present invention relates to a receiver for a radio data system (hereinafter, referred to as RD).
S receiver), particularly to a broadcast receiver using a preset channel memory.

BACKGROUND ART Broadcasting-related information such as information related to the program content is transmitted as data at the time of broadcasting from a broadcasting station by multiplex modulation, and the desired program content can be selected on the receiving side based on the demodulated data. In this way, a radio data system (RD that enables the service to be provided to radio listeners
S) there.

In this radio data system, 57KHz, which is the third harmonic of the 19KHz stereo pilot signal outside the frequency band after FM modulation, is used as the subcarrier, and this subcarrier is filtered and biphase coded. A radio data signal is amplitude-modulated by a data signal indicating information related to broadcasting such as contents, and the amplitude-modulated subcarrier is frequency-modulated to a main carrier for broadcasting.

However, not all broadcast stations broadcast such radio data at the same time as the program program, and therefore it is desirable to be able to quickly select a desired RDS broadcast station.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a broadcast receiver capable of quickly selecting a desired radio data multiplex broadcasting station.

A receiver according to the present invention is a receiver capable of receiving a multiple broadcast wave in which a data signal indicating broadcast related information is multiplexed, and a preset channel memory for storing frequency data of a plurality of preset channels and a preset scan. A controller that controls to sequentially read each frequency data of the plurality of preset channels from the preset channel memory in the mode, and tuning means that tunes to a corresponding channel frequency based on the frequency data read by the control of the controller. A detection means for detecting that the signal level of the received broadcast wave is equal to or higher than a predetermined level, and the controller is
In the preset scan mode, of the frequency data stored in the preset channel memory,
The detection means detects that the signal level of the received broadcast wave is equal to or higher than a predetermined level, and tuning of frequency data regarding a station receiving the multiplex broadcast is continued for a predetermined time by the tuning means. With
It is characterized in that the received broadcast wave obtained by being tuned by the tuning means is acoustically reproduced and output only for the predetermined time.

Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the RDS receiver as one embodiment of the present invention shown in FIG. 1, a desired station is selected by the front end 2 for the FM multiplex broadcast wave received by the antenna 1 and converted to an intermediate frequency (IF). Then, it is supplied to the IF detector 4 via the IF amplifier 3. In the front end 2, the local oscillator signal to the mixer 2b is supplied to the P circuit using the PLL circuit 2a including a programmable frequency divider.
It is obtained by the LL synthesizer method, and has a configuration in which a tuning operation is performed by controlling the frequency division ratio of the programmable frequency divider by a controller 14 described later.
The detection output of the FM detector 4 is supplied to the MPX (multiplex) demodulation circuit 5, and in the case of stereo broadcasting, L (left), R
It is separated into (right) channel audio signals.

Further, the detection output of the FM detector 4 passes through the filter 6, so that the 57 KHz subcarrier amplitude-modulated by the biphase-coded data signal, that is, the radio data signal is extracted and demodulated by the PLL circuit 7. . This demodulated output is the digital (D) PLL circuit 8 and the decoder 9.
Is supplied to. The D-PLL circuit 8 generates a data demodulation clock based on the demodulation output of the PLL circuit 7. The generated clock is supplied to the gate circuit 10. The lock detection circuit 11 detects that the D-PLL circuit 8 is locked, generates a lock detection signal, supplies the lock detection signal to the gate circuit 10, and controls the circuit 10 to be in an open state. Further, the lock detection signal is supplied to the controller 14 as a synchronization detection signal indicating that synchronized demodulated data is obtained. In the decoder 9, the bi-phase coded data signal which is the demodulated output of the PLL circuit 7 is decoded in synchronization with the clock generated in the D-PLL circuit 8.

As shown in FIG. 2, the output data of the decoder 9 is a 104-bit group unit consisting of 4 blocks of 26-bit structure, and is sequentially supplied to the group / block synchronization & error detection circuit 12. In the group / block synchronization & error detection circuit 12, the group and block are synchronized based on the 10-bit offset word assigned to the 10-bit checkword of each block, and the 16-bit information is based on the checkword. Word error detection is performed. Then, the error-detected data is supplied to the controller 14 after the error is corrected by the error correction circuit 13 at the next stage.

The controller 14 is composed of a microcomputer, and takes in the code information of each block in the radio data sequentially input in units of groups, that is, the information related to the program content of the broadcasting station currently being received and stores it in the memory 15. . In addition, in response to a preset scan command from the preset scan mode button 16a of the operation unit 16,
Each frequency data of a plurality of preset channels stored in advance in the memory 15 is sequentially read, and a frequency divider (not shown) of a programmable frequency divider (not shown) of the PLL circuit 2a forming a part of the front end 2 is used according to the frequency data. The preset scan operation is performed by sequentially controlling the frequency ratio.

The memory 15 has a nonvolatile RAM in which, for example, frequency data of six preset channels is written corresponding to the preset channel buttons 16b of "1" to "6" of the operation unit 16, and a program and data are written in advance. R
Composed of OM. The operation unit 16 is also provided with a preset scan stop button 16c for instructing to stop the preset scan operation when a desired preset channel is selected in the preset scan operation by the preset scan mode button 16a.

Further, a level detection circuit 17 for detecting that the signal level (strength) of the received broadcast wave is equal to or higher than a predetermined level based on the IF signal level in the IF amplifier 3 is provided, and the detection output of the circuit 17 is the controller 14 Is supplied to. During preset scanning, the controller 14 detects that there is a reception level for the channel frequency of each preset channel by being supplied with the detection output from the level detection circuit 17, and further, for example, when radio data is input, reception broadcasting is performed. Detecting that the wave is an RDS broadcast wave, and issuing a muting cancellation command to the muting circuit 18 provided in the subsequent stage of the MPX demodulation circuit 5 only when there is a reception level and RDS broadcasting,
Control to output the playback sound.

In the RDS receiver having such a configuration, when the preset scan mode button 16a of the operation unit 16 is operated, the operation mode becomes the preset scan mode. The processing procedure executed by the processor in the controller 14 in the preset scan mode will be described with reference to the flowchart of FIG.

In the preset scan mode, the processor first reads out the frequency data of the preset ch1 from the memory 15 (step S1), and according to the frequency data, the programmable frequency divider (of the PLL circuit 2a forming a part of the front end 2 ( A frequency division ratio (not shown) is set to tune to the corresponding channel frequency (step S2). Then, the detection output of the level detection circuit 17 is monitored to determine whether or not there is a reception level for the channel frequency of the preset channel (step S3). If there is no reception level, the preset for which the tuning operation has been performed this time is performed. It is determined whether or not the channel is 6ch (step S4), and if it is not 6ch, the frequency data of the next channel is read from the memory 15 (step S5), and then the process returns to step S2 for the channel frequency. Perform tuning operation. If it is determined that the number of channels is 6 in step S4, the process returns to step S1 and the preset CH
Repeat tuning operation from 1.

If it is determined in step S3 that there is a reception level for the tuned channel frequency, it is then determined whether the received broadcast wave is the RDS broadcast wave (step S6), and if it is not the RDS broadcast wave. , And returns to step S4 to repeat the above operation. If it is an RDS broadcast wave, that broadcast wave is received for a certain period of time (step S7), and at the same time, a muting cancellation command is issued to the muting circuit 17 to output a reproduced sound (step S8). At this time, the radio listener listens to the reproduced sound, and if it is the desired program broadcast,
Preset scan stop button 16 on the operation unit 16
Press c. When the processor detects this preset scan stop command (step S9), it responds to this and ends the preset scan operation. If the preset scan stop command is not issued, the process returns to step S4 and the above operation is repeated.

In this way, in response to the preset scan command, each frequency data of the preset channels of 1ch to 6ch is sequentially read from the memory 15 and tuned to the corresponding channel frequency, and there is a signal level of each received broadcast wave and that broadcast is By sequentially outputting the reproduced sound only during RDS broadcasting, the radio listener can listen only to RDS broadcasting with a good reception condition. Therefore, a desired RDS broadcasting station can be quickly selected in a good reception state.

In the above embodiment, the preset scan operation in which tuning is sequentially performed until the preset scan stop command is issued for the channel frequency of the preset channel has been described, but any one of "1" to "6" of the operation unit 16 is described. Of course, by pressing the preset channel button 16b, the tuning operation is performed only for the corresponding channel frequency.

As described above, according to the receiver of the present invention, in the preset scan mode, it is detected that the signal level of the received broadcast wave is equal to or higher than the predetermined level in the frequency data stored in the preset channel memory. And broadcast-related data The tuning of the frequency data related to the station transmitting the multiplex broadcast wave is continuously performed for a predetermined time, and the sound reproduction output of the received broadcast wave obtained by the tuning is performed only for the predetermined time. Therefore, it is possible to quickly and surely select the desired multiplex broadcasting station in a good reception state.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a baseband coding structure of a radio data signal, and FIG. 3 is a preset scan mode executed by a processor in the controller in FIG. 5 is a flowchart showing a processing procedure in. Description of main part symbols 1 ... Antenna 2 ... Front end 4 ... FM detector 5 ... Multiplex demodulation circuit 8 ... Digital PLL circuit 9 ... Decoder, 14 ... Controller 17 ... Level detection circuit 18 ... Muting circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-120214 (JP, A) JP-A-57-32140 (JP, A) Nikkei Electronics August 24, 1987, pages 202 to 217 page

Claims (1)

(57) [Claims] 1. A receiver capable of receiving a multiple broadcast wave in which a data signal indicating broadcast-related information is multiplexed, comprising: a preset channel memory for storing frequency data of a plurality of preset channels; and a preset scan mode. A controller that controls to sequentially read each frequency data of the plurality of preset channels from the preset channel memory; tuning means that tunes to a corresponding channel frequency based on the frequency data read by the control of the controller; A controller for detecting that the signal level of the broadcast wave is equal to or higher than a predetermined level, wherein the controller receives the frequency data stored in the preset channel memory by the detector in the preset scan mode. Broadcast wave When the signal level is detected to be equal to or higher than a predetermined level and the tuning of the frequency data relating to the station transmitting the multiplex broadcast wave is continued for a predetermined time by the tuning means, the tuning is performed for the predetermined time. A broadcasting-related data multiplex broadcasting receiver using a preset channel memory, wherein a received broadcasting wave obtained by being tuned by the tuning means is acoustically reproduced and output.